<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Handles Base64 (B) Header Encoding in Swift Mailer.
 *
 * @package    Swift
 * @subpackage Mime
 * @author     Chris Corbyn
 */
class Swift_Mime_HeaderEncoder_Base64HeaderEncoder extends Swift_Encoder_Base64Encoder implements Swift_Mime_HeaderEncoder
{
	/**
	 * Get the name of this encoding scheme.
	 * Returns the string 'B'.
	 *
	 * @return string
	 */
	public function getName()
	{
		return 'B';
	}

	/**
	 * Takes an unencoded string and produces a Base64 encoded string from it.
	 *
	 * If the charset is iso-2022-jp, it uses mb_encode_mimeheader instead of
	 * default encodeString, otherwise pass to the parent method.
	 *
	 * @param string $string string to encode
	 * @param integer $firstLineOffset
	 * @param integer $maxLineLength optional, 0 indicates the default of 76 bytes
	 * @param string $charset
	 *
	 * @return string
	 */
	public function encodeString($string, $firstLineOffset = 0, $maxLineLength = 0, $charset = 'utf-8')
	{
		if (strtolower($charset) === 'iso-2022-jp') {
			$old = mb_internal_encoding();
			mb_internal_encoding('utf-8');
			$newstring = mb_encode_mimeheader($string, $charset, $this->getName(), "\r\n");
			mb_internal_encoding($old);

			return $newstring;
		}

		return parent::encodeString($string, $firstLineOffset, $maxLineLength);
	}
}
